1. Field of the Invention
The present invention relates to an auto-focus camera including an electric exposure control device.
2. Prior Art
Most electric exposure controlled cameras are generally constructed such that camera release is prevented when the power voltage applied to the electric exposure control device is detected by a battery check circuit to have decreased to a potential at which normal exposure control operation is not guaranteed, as disclosed in U.S. Pat. No. 3,875,580.
Moreover, auto-focus cameras generally include an electric range finder for the range finding of an object, and when the power voltage applied to such a range finder declines to a potential at which normal circuit operation is not assured, the camera release is preferably made impossible to prevent an erroneous focus adjustment, as disclosed in U.S. Pat. No. 3,442,193. Additionally, prior art range finder devices permit no stable circuit operation immediately after the power has been applied, due to a delayed response to the photoelectric element receiving light from an object and an equivalent capacitance inherent in the circuit. It actually takes some time for the circuit operation to become stable, thus guaranteeing no correct focus adjustment only on condition that the power voltage is at sufficient potential.